Patent attributes
A valve assembly includes a valve body with a central passage, an upstream end for receiving a fluid, and a downstream end for discharging the fluid. A segment ball valve rotates between a valve open position to allow the fluid to flow through the central passage, and a valve closed position to prevent the fluid from flowing through the central passage. A check valve located within the central passage downstream from the segment ball valve is biased to prevent the fluid from traveling upstream through the central passage, and to allow the fluid to travel downstream past the check valve. A locking mechanism secures the check valve in a locked position to prevent the fluid from flowing past the check valve. A sealable cavity is located between the segment ball valve and the check valve, to contain a neutral media to achieve a double block and bleed feature.